五带虻溶纤活性蛋白的纯化和性质

PURIFICATION AND CHARACTERIZATION OF THE FIBRINOLYTIC COMPONENT OF TABANUS QUINQUECINCTUS RICARDO

五带虻ＴａｂａｎｕｓｑｕｉｎｑｕｅｃｉｎｃｔｕｓＲｉｃａｒｄｏ腹部匀浆液经硫酸铵沉淀、ＳｅｐｈａｄｅｘＧ－７５凝胶层析、Ｆｉｂｒｉｎ－Ｓｅｐｈａｒｏｓｅ４Ｂ亲和层析和电泳制备等方法纯化后，获得在ＳＤＳ－ＰＡＧＥ图谱上呈现单一区带的溶纤活性蛋白。该蛋白质既具有纤溶酶作用，又具有激活纤溶酶原的作用，其分子量为４０ｋＤ，等电点为４．５，最适作用ｐＨ为９．０，最适作用温度为２８℃，３７℃处理２ｈ活性完全丧失，Ｃａ２＋、Ｍｎ２＋、Ｃｕ２＋、Ｚｎ２＋、Ｈｇ２＋和ＰＭＳＦ能抑制其活性。

The fibrinolytic component(FC) separated from the homogenate of abdomen of Tabanus quinquecinctus Ricardo was showed to possess both fibrinolytic enzyme and plasminogen activator activities. After ammonium sulphate precipitation, Sephadex G75 gel filtration, FibrinSepharose 4B affinity chromatography and elution from electrophoresis, it appeared as a single band corresponding to molecular weight(MW) of approximately 40kD on SDSPAGE and its isoelectric point was about 45 on IEF. Its optimal reaction pH was 90 and optimal reaction temperature was 28℃. The activity of FC was totally lost after incubation at 37℃ for two hours and could be inhibited by Ca2+,Mn2+,Cu2+,Zn2+,Hg2+ and PMSF.